/**** 
* Plugins
****/ 
var tween = LK.import("@upit/tween.v1");

/**** 
* Classes
****/ 
var Boss = Container.expand(function () {
	var self = Container.call(this);
	var bossGraphics = self.attachAsset('boss', {
		anchorX: 0.5,
		anchorY: 0.5
	});
	self.health = 3;
	self.speed = 2;
	self.moveDirection = 1;
	self.update = function () {
		self.x += self.speed * self.moveDirection;
		if (self.x <= 60 || self.x >= 2048 - 60) {
			self.moveDirection *= -1;
		}
	};
	return self;
});
var Enemy = Container.expand(function () {
	var self = Container.call(this);
	var enemyGraphics = self.attachAsset('enemy', {
		anchorX: 0.5,
		anchorY: 0.5
	});
	self.speed = 3;
	self.update = function () {
		self.y += self.speed;
	};
	return self;
});
var Fireball = Container.expand(function () {
	var self = Container.call(this);
	var fireballGraphics = self.attachAsset('fireball', {
		anchorX: 0.5,
		anchorY: 0.5
	});
	self.speed = -15;
	self.update = function () {
		self.y += self.speed;
	};
	return self;
});
var Star = Container.expand(function () {
	var self = Container.call(this);
	var starGraphics = self.attachAsset('star', {
		anchorX: 0.5,
		anchorY: 0.5
	});
	self.speed = 1;
	self.update = function () {
		self.y += self.speed;
		if (self.y > 2732) {
			self.y = -10;
			self.x = Math.random() * 2048;
		}
	};
	return self;
});

/**** 
* Initialize Game
****/ 
var game = new LK.Game({
	backgroundColor: 0x000011
});

/**** 
* Game Code
****/ 
var player;
var fireballs = [];
var enemies = [];
var stars = [];
var boss = null;
var lives = 3;
var enemiesDefeated = 0;
var gameStarted = true;
var bossSpawned = false;
var dragNode = null;
var livesText = new Text2('Lives: 3', {
	size: 80,
	fill: 0xFFFFFF
});
livesText.anchor.set(0.5, 0);
LK.gui.topRight.addChild(livesText);
var scoreText = new Text2('Enemies: 0/50', {
	size: 80,
	fill: 0xFFFFFF
});
scoreText.anchor.set(0.5, 0);
LK.gui.top.addChild(scoreText);
function createPlayer() {
	player = game.addChild(new Container());
	var playerGraphics = player.attachAsset('player', {
		anchorX: 0.5,
		anchorY: 0.5
	});
	player.x = 2048 / 2;
	player.y = 2732 - 120;
}
function createStarfield() {
	for (var i = 0; i < 50; i++) {
		var star = game.addChild(new Star());
		star.x = Math.random() * 2048;
		star.y = Math.random() * 2732;
		stars.push(star);
	}
}
function spawnEnemy() {
	if (!bossSpawned && enemiesDefeated < 45) {
		var enemy = game.addChild(new Enemy());
		enemy.x = Math.random() * (2048 - 100) + 50;
		enemy.y = -60;
		enemy.lastY = enemy.y;
		enemy.lastIntersecting = false;
		enemies.push(enemy);
	}
}
function spawnBoss() {
	if (!bossSpawned && enemiesDefeated >= 45) {
		boss = game.addChild(new Boss());
		boss.x = 2048 / 2;
		boss.y = 200;
		boss.lastIntersecting = false;
		bossSpawned = true;
		LK.playMusic('bossMusic', {
			loop: true
		});
	}
}
function fireFireball() {
	var fireball = game.addChild(new Fireball());
	fireball.x = player.x;
	fireball.y = player.y - 50;
	fireball.lastY = fireball.y;
	fireballs.push(fireball);
	LK.getSound('shoot').play();
}
createPlayer();
createStarfield();
LK.playMusic('spaceMusic', {
	loop: true
});
var spawnTimer = LK.setInterval(function () {
	spawnEnemy();
}, 800);
var fireTimer = LK.setInterval(function () {
	if (gameStarted) {
		fireFireball();
	}
}, 400);
game.move = function (x, y, obj) {
	if (gameStarted) {
		player.x = x;
		player.y = y;
	}
};
game.down = function (x, y, obj) {
	dragNode = player;
	if (gameStarted) {
		player.x = x;
		player.y = y;
	}
};
game.up = function (x, y, obj) {
	dragNode = null;
};
game.update = function () {
	for (var s = stars.length - 1; s >= 0; s--) {
		stars[s].update();
	}
	for (var f = fireballs.length - 1; f >= 0; f--) {
		var fireball = fireballs[f];
		fireball.update();
		if (fireball.lastY === undefined) {
			fireball.lastY = fireball.y;
		}
		if (fireball.lastY >= -50 && fireball.y < -50) {
			fireball.destroy();
			fireballs.splice(f, 1);
			continue;
		}
		for (var e = enemies.length - 1; e >= 0; e--) {
			var enemy = enemies[e];
			if (fireball.intersects(enemy)) {
				LK.getSound('explosion').play();
				fireball.destroy();
				fireballs.splice(f, 1);
				enemy.destroy();
				enemies.splice(e, 1);
				enemiesDefeated++;
				scoreText.setText('Enemies: ' + enemiesDefeated + '/50');
				break;
			}
		}
		if (boss && fireball.intersects(boss)) {
			LK.getSound('explosion').play();
			fireball.destroy();
			fireballs.splice(f, 1);
			boss.health--;
			if (boss.health <= 0) {
				boss.destroy();
				LK.effects.flashScreen(0x00ff00, 1000);
				LK.showYouWin();
			}
			break;
		}
		fireball.lastY = fireball.y;
	}
	for (var e = enemies.length - 1; e >= 0; e--) {
		var enemy = enemies[e];
		enemy.update();
		if (enemy.lastY === undefined) {
			enemy.lastY = enemy.y;
		}
		if (enemy.lastY >= -50 && enemy.y < -50) {
			enemy.destroy();
			enemies.splice(e, 1);
			continue;
		}
		if (enemy.y > 2732) {
			enemy.destroy();
			enemies.splice(e, 1);
			continue;
		}
		var currentIntersecting = enemy.intersects(player);
		if (!enemy.lastIntersecting && currentIntersecting) {
			LK.getSound('hit').play();
			LK.effects.flashScreen(0xff0000, 500);
			lives--;
			livesText.setText('Lives: ' + lives);
			enemy.destroy();
			enemies.splice(e, 1);
			if (lives <= 0) {
				gameStarted = false;
				LK.clearInterval(spawnTimer);
				LK.clearInterval(fireTimer);
				LK.effects.flashScreen(0xff0000, 1000);
				LK.playMusic('gameOverMusic', {
					loop: false
				});
				LK.showGameOver();
			}
			continue;
		}
		enemy.lastIntersecting = currentIntersecting;
		enemy.lastY = enemy.y;
	}
	if (boss) {
		boss.update();
		if (boss.lastIntersecting === undefined) {
			boss.lastIntersecting = false;
		}
		var currentBossIntersecting = boss.intersects(player);
		if (!boss.lastIntersecting && currentBossIntersecting) {
			LK.getSound('hit').play();
			LK.effects.flashScreen(0xff0000, 500);
			lives--;
			livesText.setText('Lives: ' + lives);
			if (lives <= 0) {
				gameStarted = false;
				LK.clearInterval(spawnTimer);
				LK.clearInterval(fireTimer);
				LK.effects.flashScreen(0xff0000, 1000);
				LK.playMusic('gameOverMusic', {
					loop: false
				});
				LK.showGameOver();
			}
		}
		boss.lastIntersecting = currentBossIntersecting;
	}
	if (enemiesDefeated >= 45 && !bossSpawned) {
		spawnBoss();
	}
};

===================================================================
--- original.js
+++ change.js
@@ -129,8 +129,11 @@
 		boss.x = 2048 / 2;
 		boss.y = 200;
 		boss.lastIntersecting = false;
 		bossSpawned = true;
+		LK.playMusic('bossMusic', {
+			loop: true
+		});
 	}
 }
 function fireFireball() {
 	var fireball = game.addChild(new Fireball());
@@ -141,8 +144,11 @@
 	LK.getSound('shoot').play();
 }
 createPlayer();
 createStarfield();
+LK.playMusic('spaceMusic', {
+	loop: true
+});
 var spawnTimer = LK.setInterval(function () {
 	spawnEnemy();
 }, 800);
 var fireTimer = LK.setInterval(function () {
@@ -236,8 +242,11 @@
 				gameStarted = false;
 				LK.clearInterval(spawnTimer);
 				LK.clearInterval(fireTimer);
 				LK.effects.flashScreen(0xff0000, 1000);
+				LK.playMusic('gameOverMusic', {
+					loop: false
+				});
 				LK.showGameOver();
 			}
 			continue;
 		}
@@ -259,8 +268,11 @@
 				gameStarted = false;
 				LK.clearInterval(spawnTimer);
 				LK.clearInterval(fireTimer);
 				LK.effects.flashScreen(0xff0000, 1000);
+				LK.playMusic('gameOverMusic', {
+					loop: false
+				});
 				LK.showGameOver();
 			}
 		}
 		boss.lastIntersecting = currentBossIntersecting;